1. Field of the Invention
The present invention relates to an operation input system and an operation input method for receiving an input operation from a user via an operation window, in particular, an operation input system and an operation input method for receiving the input of security information, such as a password or the like.
2. Description of Related Art
In case that the security information, such as a password, is input via an operation panel, when another person is near the operation panel, another person secretly looks at the operation panel or the motion of the user's hand during the input of the security information. Therefore, there is some possibility that the contents of the input security information are leaked.
In order to prevent the leak of the information from being caused by secretly looking at the operation panel or the like, for example, the method in which even though another person secretly looks at the motion of the user's hand or the like, the input contents cannot be easily guessed by changing the arrangement in the software numerical keypad displayed on the operation panel, is proposed (See Japanese Patent Application Publication No. 2005-258838).
Even though the arrangement in the software numerical keypad is changed every time, as shown in FIG. 16, when another person secretly looks at the operation window of the operation panel from behind the user, it is not possible to prevent the leak of the input contents. Similarly, as shown in FIG. 17, when another user secretly monitors the operation window by using the video camera which is intentionally installed, it is not possible to prevent the leak of the input contents.